Low cost sealed connector and method of making same

ABSTRACT

A low cost sealed electrical connector and method of making the same in which a conductor terminating in an electrical contact is slidably mounted in the rear end of a passage in a connector body and a radially deformable sealing element surrounding the conductor is forced into the annular space between the conductor and the wall of the passage to provide a seal therebetween. Preferably, the sealing element is attached to the conductorcontact assembly prior to inserting the assembly into the connector body. The invention may be used in any application where it is desired to seal a conductor within a wall or body. A special form of a sealing element is disclosed which assures a moisture-tight seal between the conductor and the body in which it is mounted.

United States Patent 1191 Barr [ LOW COST SEALED CONNECTOR AND METHOD OFMAKING SAME [75] Inventor: John E. Barr, Brea, Califv [73] Assignee:International Telephone and Telegraph Corporation, New York, NY.

22 Filed: Oct. 17, 1972 21 Appl. No.: 298,416

[ 51 Jan. 22, 1974 24,441 12/1914 Great Britain 339/103 R PrimaryExaminerJoseph H. McGlynn Attorney, Agent, or Firm-Thomas L. Peterson[57] ABSTRACT A low cost sealed electrical connector and method ofmaking the same in which a conductor terminating in an electricalcontact is slidably mounted in the rear end of a passage in a connectorbody and a radially deformable sealing element surrounding the conductoris forced into the annular space between the conductor and the wall ofthe passage to provide a seal therebetween. Preferably, the sealingelement is attached to the conductor-contact assembly prior to insertingthe assembly into the connector body. The invention may be used in anyapplication where it is desired to seal a conductor within a wall orbody. A special form of a sealing element is disclosed which assures amoisture-tight seal between the conductor and the body in which it ismounted.

12 Claims, 6 Drawing Figures LOW COST SEALED CONNECTOR AND METHOD OFMAKING SAME BACKGROUND OF THE INVENTION This invention relates to methodand means for providing a low cost seal between a conductor and a bodyin which the conductor is mounted and, more specifically, to a low costseal for an electrical connector.

DESCRIPTION OF THE PRIOR ART There are generally two different types ofelectrical connectors, namely, sealed and unsealed. The term, sealed, asused herein refers to the ability of a connector, that is, the matedplug and receptacle members, to prevent the intrusion of moisture orother contaminants into the area of the connector containing theelectrical contacts.

There are presently available a number of electrical connectors whichare of the sealed type. However, methods to achieve scaling in theseconnectors are expensive and have functional limitations which renderthe connectors unacceptable for some applications. In one form of such asealed electrical connector, an elastomeric sealing member is faced oneach end of the respective parts of the connector. The central sealingmember is referred to in the art as an interfacial seal. To function,this seal must be held in a compressed condition against the matingsurfaces of the connector parts. This requires some form of positivecoupling or latching between such parts. Loss of this pressure betweenthe parts will allow moisture entry into the connector. In another formof a sealed connector, the entire body of the connector is formed ofelastomeric material. The central seal is provided in this type ofconnector by a deformable lip on either the plug or receptacle member ofthe connector.

The rear seal in each of these connectors is provided by a radiallyinwardly directed deformable lip adjacent the rear end of the passagesin the connector. After a contact is mounted in a'passage, the lip willform a seal around the insulation coating on the conductor connectedthereto. This arrangement has the disadvantage that when the contact isinserted into the connector body through the rear sealing member portionof the body, sharp edges on the contact sometimes scar the sealing ribthereby preventing a complete seal from being formed.

SUMMARY OF THE INVENTION It is the principal object of the presentinvention to provide an improved method of providing a seal between aconductor and a body in which the conductor is mounted.

Another object of the invention is to provide an improvedconductor-contact assembly which may be inserted through the rear of aconnector body and sealed thereto without damage occurring to the seal.

According to the principal aspect of the present invention, there isprovided a method of mounting a conductor in a passage of a connectorbody in sealing relationship therewith. Initially, there is provided aconductor terminating in electrical contact having a maximum crosssection less than that of the rear of the connector body passage. Theconductor is inserted into the rear of the passage until the contactreaches the forward end thereof. A radially deformable hollow sealingelement which surrounds the conductor is then forced into the annularspace between the conductor and the wall of the passage to provide aseal therebetween. Preferably, the sealing element is attached either tothe connector body or the conductor-contact assembly prior to insertingthe assembly into the connector body. In the preferred embodiment, thesealing element is carried by the conductor-contact assembly by means ofa forwardly extending tongue on the sealing element which is heldbetween the crimp barrel of the contact and the conductor insulatorcover.

According to another aspect of the invention, there is provided animproved sealing element comprising a collet which is formed with alongitudinally extending slot through one wall thereof definingtherebetween opposed wall faces. A radially extending deformable rib isformed on one of the faces between the ends of the collet. When thesealing member is forced into the annular space between the conductorand the wall of the passage in the connector body receiving the contact,the collet will contract and the rib will deform providing a sealbetween the faces of the slot. The rib will also expand radiallyproviding pressure for a seal against the conductor insulator and thewall of the passage in the connector body.

Other aspects and advantages of the invention will become more readilyappreciated by reference to the following detailed description whenconsidered in connection with the accompanying drawing in which likereference numerals designate like or corresponding parts throughout thevarious views.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a partial longitudinalsectional view through mated receptacle and plug members of a connectorembodying the features of the present invention;

FIG. 2 is a side elevation of one end of a conductorcontact assemblywhich is utilized in making the connector illustrated in FIG. 1.

FIG. 3 is an enlarged perspective view of the preferred sealing elementutilized in the present invention;

FIG. 4 is a longitudinal sectional view taken along line 44 of FIG. 3;

FIG. 5 is a sectional view similar to FIG. 4 showing a modified form ofthe sealing element of the invention; and

FIG. 6 is a partial sectional view of another embodiment of theinvention in which an insulated conductor is sealed within a wall.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference is now made to thedrawings in detail, particularly FIG. 14, which illustrate the preferredform of the invention as it is applied to an electrical connector,generally indicated 10. The connector comprises mated receptacle andplug members 12 and 14, respectively. The plug member 14 is formed witha pair of cylindrical forwardly extending projections 16 which areslidably received in mating recesses 18 formed in the receptacle 12. Thebodies of the plug and receptacle are formed of a suitable insulatingmaterial, such as a thermoplastic. Although two projections 16 andrecesses 18 are shown, it will be apparent that any number may beprovided depending upon the particular application of the connector.

Sealing ribs 20 are formed on each of the projections 16 of the plugmember 14. Although two ribs are shown on each projection, any number ofribs may be provided. These ribs are dimensioned so that they have aninterference fit with the walls of the recesses 18 so that an effectivemoisture-proof seal is formed at the forward ends of the plug andreceptacle members of the connector when the two parts are matedtogether as illustrated in FIG. 1.

The ribs 20 provide a central seal between the plug and receptaclemembers of the connector which is high efficient and inexpensive. Theseal is particularly advantageous in that it is not sensitive to theaxial position of the plug member within the receptacle member. Aninterfacial seal as utilized in prior art connectors canot allow for anyaxial displacement between the connector parts and still provide aneffective moisture barrier as in the present invention.

The plug member 14 of the connector is provided with a pair oflongitudinally extending passages 22, each of which is coaxial with arespective one of the projections 16. The passages extend from theforward end 24 of the projections to the rear end 26 of the plug body.The receptacle connector 12 is likewise formed with a pair oflongitudinally extending passages 28 which pass through the receptaclebody and are aligned with the passages 22.

Female contact elements 30 are mounted in the projections 16 of theplug. Male contact elements 32 which are mounted in the passages 28 inthe receptacle connector member extend into the recesses 18 for slidingengagement into the female contact elements 30 when the connectormembers are mated. The manner in which the contact elements 30 and 32are connected to their respective conductors and the the manner in whichthe conductors are sealed within their respective connector members areidentical. Thus, for the purpose of this description, only the mountingof the female contact elements 30 to their conductors and the sealing ofsuch conductors in the plug connecter member will be described.

Each passage 22 includes a forward end 34 and a rear end 36 which areseparated by an inwardly extending flange 38 which defines a restrictedbore interconnecting the ends 34 and 36 of the passage. The contact 30embodies at its rear end a barrel 40 which is crimped upon theinsulation cover 42 of an insulated electrical conductor, generallyindicated 44. The insulation cover 42 encloses a plurality of wires 46which are attached to the contact by crimping intermediate section 48thereof. Forward of the crimped section 48 is an outwardly extendingflange 50 on the contact 30 which abuts against a rearwardly facingshoulder 52 formed bythe flange 38. The contact is formed with a pair ofspring tines 54 the rear ends of which engage a forwardly facingshoulder 56 provided by the flange 38. The tines 54 and flange 50 of thecontact cooperate with the shoulders provided by flange 38 of the plugbody to retain the contact in the body. A sealing element or collet 60positioned in the rear end 36 of passage 22 serves to seal the insulatedconductor 44 in the rear of the plug body.

As best seen in FIG. 3, the collet 60 comprises a generally cylindricalbody which is formed with a longitudinally extending slot 62 whichpasses through one wall thereof to provide opposed faces 64 and 66. Therear of the collet is formed with a radially outwardly extending flange68 while the forward end of the collet is chamfered to provide afrusto-conical lead surface 70 which facilitates insertion of the colletinto the passage 22. As best seen in FIG. 4, the interior wall of thecollet includes a flared forward portion 72 and flared rear portion 74,said portions joining intermediate the forward and rear ends 76 and 78,respectively, of the collect to provide an inner reduced diametersection 80. Alternatively, as seen in FIG. 5, the passage extendingthrough the collet 60 may be cylindrical in configuration, and thereduced diameter portion may be in the form of a radially inwardlyextending rib as seen.

A generally radially extending rib 82 is formed on the face 64 of thecollet 60 generally intermediate the ends 76 and 78 thereof, that is,adjacent the section 80 of the collet. More than one rib 82 may beprovided if desired. The collet is preferably formed of a thermoplasticmaterial so that the rib 82 is deformable.

The collet is also formed with a forwardly extending integral, flexibletongue 84. The purpose of the tongue 84 can be best seen with referenceto the conductorcontact assembly, generally designated 86, illustratedin FIG. 2. In this assembly, the tongue 84 is held between the crimpbarrel 40 of the contact and the insulation cover 42 of the conductor44. The assembly 86 is formed by first inserting the collet 60 on theinsulated conductor 44 which is stripped of its insulation cover at itsforward end to expose the wires '46. Thereafter, the contact ispositioned on the conductor 44 with crimp barrel 40 surrounding the endof the insulation cover 42 and the tongue 84 of the collet 60 positionedtherebetween. The intermediate section 48 of the contact and the barrel40 are then crimped to secure the contact to the wires 46 and theinsulation cover 42, respectively, thus causing the tongue 84 to betightly gripped between the barrel and the insulation cover.

At this point, it should be noted that several important dimensionalrelationships are required between the contact 30, collet 60, and thepassage 22 extending through plug connector member 14. First, themaximum cross-section of the contact 30 is less than the cross-sectionof the rear end 36 of passage 22 so that the contact may be slidablyinserted into the passage without scarring the surface of the passage.The diameter of the rear end 36 of passage 22 is also such that when thecollet 50 is forced into the passage around the insulated conductor 44,the collet will contract or radially deform to such an extent that therib 82 on the collet will engage face 66 thereon and will deform toeffect a moisture-tight seal between the opposed faces 64 and 66. Ofcourse, the forward end 76 of the collet must have sufficiently smalldiameter to allow such end to enter into the annular space between theconductor 44 and wall of the passage 22. In addition, the diameter ofthe central reduce section 80 of the collet is slightly greater than theouter diameter of the insulated conductor 44, yet sufficiently small sothat when the collet is forced into the passage 22, the section 80thereof will squeeze the insulator coating 42 as indicated at 90 in FIG.1.

In mounting the conductor-contact assembly 86 into the plug connectormember 14, the contact 30 is introduced into the rear end 36 of passage22 and is moved forwardly until the tines 54 engage the shoulder 52 onflange 38. Further forward movement of the contact will cause the tines54 to contract until they pass beyond the flange 38 and reach theposition illustrated in FIG. 1 where the tines spring outwardly andengage the shoulder 56 on the flange 38, thus locking the contact in theplug body. During such forward movement of the contact 30 in the plugbody, the frusto-conical lead surface 70 of the collet 60 enters therear end 36 of pas sage 22. After the contact 30 is properly positionedin the plug body, a suitable tool, not shown, is positioned behind thecollet 60 and moved forwardlyto force the collet into the passage 22until the flange 68 engages the rear surface 26 of the plug body. Thismovement of the collet relative to the contact 30 causes the tongue 84to fold or crimp as seen in FIG. 1. Forcing the collet into the passagecauses the collet to radially contract, thus squeezing the insulatedcover 42 on the conductor 44 at the point 90 which is a localized areaof high pressure loading thereby effecting moisture-tight sealtherebetween. The slot 62 in the collet is simultaneously sealed bydeformation of the rib 82 located at the point of maximum compression ofthe collet. The rib 82 also deforms radially providing pressure for aseal at the inside diameter of the collet against the insulation cover42 of the conductor and on the outside diameter of the collet at thewall of the passage 36. Thus, it is seen that the collet 60 provides amoisture-tight seal between the conductor 44 and the wall of passage 36of the plug body. In addition to performing a moisture-seal function,the collet also provides two other benefits. First, the collet providesa wire strain relief to assist in retaining the contact 30 in the plugbody and reduces or eliminates wire mechanical loads at the contactretention area, namely, at points 40 and 48. Second, the proximity ofthe seal to the contact in the plug gives a second point of support forthe contact and assists in positioning and stabilizing this member inthe plug.

While the collet has been shown as being a split cylindrical body, thepresent invention can also be practiced by employing simply a continuouscylindrical collet, that is, one without the slot 62. In this case, thecollet must be formed of a sufficiently deformable material so that whenthe collet is forced into the annular space between the conductor 44 andthe wall of passage 36, it will contract to provide a moisture-tightseal therebetween. Such a collet could be frictionally retained on theconductor 44 prior to inserting the conductorcontact assembly in theplug body, thus eliminating the tongue 84. Moreover, both the split andcontinuous collets may be retained upon the plug body 14 by a suitableplastic strip (not shown) rather than upon the conductor 44 as seen inFIG. 2 prior to inserting the conductor-contact assembly into thepassage 22. However, the attaching of the collet 60 on the conductor 44is most practical when the contact 30 is of the crimptype, as shown. Themounting of the collet on the conductor is significant in massproduction as the contact and collet can be attached to the wires of theconductor 44 in a single operation. The collet also becomes permanentlyattached to the conductor and, thus, does not require special handlingwhen it is desired to form the seal between the conductor and the plugbody. Moreover, this arrangement permits the installation of theconductor-contact assembly 86 into the passage 36 of the plug body inone operation. However, the advantages of providing a good seal canstill be obtained in accordance with the present invention by simplyutilizing the collet 60 disconnected from the assembly 86.

In addition, the collet 60 of the present invention may be utilized forsealing conductors in other than electrical connector assemblies. Forexample, as seen in FIG. 6, the collet may be utilized to seal aconductor or cable 94 in a wall 96.

Although I have herein shown and described my invention in what I haveconceived to be the most practical preferred embodiments, it isrecognized that departures may be made therefrom within the scope of myinvention which is not to be limited to the details disclosed herein butis to be accorded the full scope of the claims so as to embrace any andall equivalent structures and methods.

I claim:

1. An electrical contact assembly for mounting in an electricalconnector insulator comprising:

a conductor having an insulation cover thereon except for an end portionthereof:

a contact member secured to said end portion;

a sealing element surrounding said conductor adjacent to said contactmember;

said sealing element formed with an elongated, forwardly extendingflexible tongue thereon;

said contact member embodying a barrel crimped to said insulation coveradjacent to said end portion of said conductor; and

the forward end of said tongue only being held between said barrel andsaid insulation cover.

2. An electrical contact assembly for mounting in an electricalconnector insulator comprising:

a conductor having an insulation cover thereon except for an end portionthereof;

a contact member secured to said end portion;

a sealing element surrounding said conductor adjacent to said contactmember and being retained on said conductor;

said sealing element comprising a hollow body formed with alongitudinally extending slot through the wall thereof defining opposedfaces; and

a generally radially extending deformable rib formed on one of saidfaces.

3. An assembly as set forth in claim 2 wherein:

a portion of the interior wall of said hollow body between the ends ofsaid body has a cross-section less than that at said ends.

4. An assembly as set forth in claim 3 wherein: said sealing element isformed of a plastic material.

5. An electrical contact assembly for mounting in an electricalconnector insulator comprising:

a conductor having an insulation cover thereon except for an end portionthereof;

a contact member secured to said end portion;

a sealing element surrounding said conductor adjacent to said contactmember and being retained on said conductor;

said sealing element comprising a generally cylindrical body formed of aplastic material, said body being formed with a longitudinally extendingslot through the wall thereof defining opposed faces;

a generally radially extending integral rib formed on one of said faces;

a portion of the interior wall of said body between the ends thereofhaving a cross-section less than that at said ends;

an integral forwardly extending tongue on said body;

said contact member embodying a barrel crimpedto a section of saidinsulated conductor; and

said tongue being held between said barrel and said section.

6. A seal assembly comprising:

a base member having a passage therethrough;

an insulated conductor extending through said passage;

a sealing element surrounding said conductor in sealing relationtherewith, the outer surface of said element being in sealing engagementwith the wall of said passage;

said sealing element comprising a hollow body formed with alongitudinally extending slot through the wall thereof defining opposedfaces; and

a generally radially extending deformable rib formed on one of saidfaces.

7. An assembly as set forth in claim 6 wherein:

a portion of the interior wall of said hollow body between the ends ofsaid body has a cross-section less than that at said ends.

8. An assembly as set forth in claim 6 wherein:

said base member comprises an electrical connector insulator embodyingsaid passage; and

said conductor having an electrical contact mounted thereon, saidcontact being retained in said passage.

9. An assembly as set forth in claim 8 wherein:

said passage is elongated;

said sealing element is mounted in one end of said passage; and

the cross-section of said one end of said passage is greater than themaximum cross-section of said contact.

10. An electrical connector comprising:

mating plug and receptacle connector members each formed with alongitudinally extending passage having a contact mounted in the forwardend of said passage;

said plug connector member embodying a forwardly extending projectionslidably received in a mating recess in said receptable connectormember, said projection being formed with a sealing rib extending aboutits outer surface and having an interference fit with the wall of saidrecess;

a conductor extending into each passage and being connected to therespective contact therein;

a separate sealing element surrounding each said conductor adjacent therear end of said passage, said sealing element being in sealingengagement connector insulator member formed with a passage having aforward end and rear end comprising the steps of:

providing a conductor member terminating with an electrical contacthaving a cross-section less than that of said rear end of said passage,said conductor member being encircled by a radially deformable hollowsealing element having a forwardly extenidng, elongated flexible tonguethereon secured at its forward end only to said conductor member;

sliding said conductor member through said rear end of said passageuntil said contact reaches the forward end thereof; and

thereafter forcing said sealing element into the annular space betweensaid conductor member and said rear end of said passage causing saidtongue to fold and providing a seal between said conductor member andthe wall of said passage.

1. An electrical contact assembly for mounting in an electricalconnector insulator comprising: a conductor having an insulation coverthereon except for an end portion thereof: a contact member secured tosaid end portion; a sealing element surrounding said conductor adjacentto said contact member; said sealing element formed with an elongated,forwardly extending flexible tongue thereon; said contact memberembodying a barrel crimped to said insulation cover adjacent to said endportion of said conductor; and the forward end of said tongue only beingheld between said barrel and said insulation cover.
 2. An electricalcontact assembly for mounting in an electrical connector insulatorcomprising: a conductor having an insulation cover thereon except for anend portion thereof; a contact member secured to said end portion; asealing element surrounding said conductor adjacent to said contactmember and being retained on said conductor; said sealing elementcomprising a hollow body formed with a longitudinally extending slotthrough the wall thereof defining opposed faces; and a generallyradially extending deformable rib formed on one of said faces.
 3. Anassembly as set forth in claim 2 wherein: a portion of the interior wallof said hollow body between the ends of said body has a cross-sectionless than that at said ends.
 4. An assembly as set forth in claim 3wherein: said sealing element is formed of a plastic material.
 5. Anelectrical contact assembly for mounting in an electrical connectorinsulator comprising: a conductor having an insulation cover thereonexcept for an end portion thereof; a contact member secured to said endportion; a sealing element surrounding said conductor adjacent to saidcontact member and being retained on said conductor; said sealingelement comprising a generally cylindrical body formed of a plasticmaterial, said body being formed with a longitudinally extending slotthrough the wall thereof defining opposed faces; a generally radiallyextending integral rib formed on one of said faces; a portion of theinterior wall of said body between the ends thereof having across-section less than that at said ends; an integral forwardlyextending tongue on said body; said contact member embodying a barrelcrimped to a section of said insulated conductor; and said tongue beingheld between said barrel and said section.
 6. A seal assemblycomprising: a base member having a passage therethrough; an insulatedconductor extending through said passage; a sealing element surroundingsaid conductor in sealing relation therewith, the outer surface of saidelement being in sealing engagement with the wall of said passage; saidsealing element comprising a hollow body formed with a longitudinallyextending slot through the wall thereof defining opposed faces; and agenerally radially extending deformable rib formed on one of said faces.7. An assembly as set forth in claim 6 wherein: a portion of theinterior wall of said hollow body between the ends of said body has across-section less than that at said ends.
 8. An assembly as set forthin claim 6 wherein: said base member comprises an electrical connectorinsulator embodying said passage; and said conductor having anelectrical contact mounted thereon, said contact being retained in saidpassage.
 9. An assembly as set forth in claim 8 wherein: said passage iselongated; said sealing element is mounted in one end of said passage;and the cross-section of said one end of said passage is greater thanthe maximum cross-section of said contact.
 10. An electrical connectorcomprising: mating plug and receptacle connector members each formedwith a longitudinally extending passage having a contact mounted in theforward end of said passage; said plug connector member embodying aforwardly extending projection slidably received in a mating recess insaid receptable connector member, said projection being formed with asealing rib extending about its outer surface and having an interferencefit with the wall of said recess; a conductor extending into eachpassage and being connected to the respective contact therein; aseparate sealing element surrounding each said conductor adjacent therear end of said passage, said sealing element being in sealingengagement with both said conductor and the wall of said passage; saidsealing element comprising a hollow body formed with a longitudinallyextending slot through the wall thereof defining opposed faces; and agenerally radially extending deformable rib formed on one of said faces.11. A connector as set forth in claim 10 wherein: a portion of theinterior of said hollow body between the ends of said body has across-section less than that at said ends.
 12. A method of mounting anelectrical contact in a connector insulator member formed with a passagehaving a forward end and rear end comprising the steps of: providing aconductor member terminAting with an electrical contact having across-section less than that of said rear end of said passage, saidconductor member being encircled by a radially deformable hollow sealingelement having a forwardly extenidng, elongated flexible tongue thereonsecured at its forward end only to said conductor member; sliding saidconductor member through said rear end of said passage until saidcontact reaches the forward end thereof; and thereafter forcing saidsealing element into the annular space between said conductor member andsaid rear end of said passage causing said tongue to fold and providinga seal between said conductor member and the wall of said passage.